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Rename SortMem and VacuumMem to work_mem and maintenance_work_mem.
Make btree index creation and initial validation of foreign-key constraints use maintenance_work_mem rather than work_mem as their memory limit. Add some code to guc.c to allow these variables to be referenced by their old names in SHOW and SET commands, for backwards compatibility.
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@ -1,5 +1,5 @@
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<!--
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$PostgreSQL: pgsql/doc/src/sgml/perform.sgml,v 1.40 2004/01/11 05:46:58 neilc Exp $
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$PostgreSQL: pgsql/doc/src/sgml/perform.sgml,v 1.41 2004/02/03 17:34:02 tgl Exp $
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-->
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<chapter id="performance-tips">
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@ -684,16 +684,18 @@ SELECT * FROM x, y, a, b, c WHERE something AND somethingelse;
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</para>
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</sect2>
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<sect2 id="populate-sort-mem">
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<title>Increase <varname>sort_mem</varname></title>
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<sect2 id="populate-work-mem">
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<title>Increase <varname>maintenance_work_mem</varname></title>
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<para>
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Temporarily increasing the <varname>sort_mem</varname>
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Temporarily increasing the <varname>maintenance_work_mem</varname>
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configuration variable when restoring large amounts of data can
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lead to improved performance. This is because when a B-tree index
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is created from scratch, the existing content of the table needs
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to be sorted. Allowing the merge sort to use more buffer pages
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means that fewer merge passes will be required.
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to be sorted. Allowing the merge sort to use more memory
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means that fewer merge passes will be required. A larger setting for
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<varname>maintenance_work_mem</varname> may also speed up validation
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of foreign-key constraints.
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</para>
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</sect2>
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